JP7552123B2 - Toner conveying device and image forming apparatus equipped with the toner conveying device - Google Patents

Description

The present invention relates to a toner transport device that transports toner.

Image forming devices such as copiers and printers that form images on sheet materials such as printing paper by electrophotography are equipped with developing devices. A developer containing toner is stored inside the developing device. The developing device develops an electrostatic latent image formed on an image carrier such as a photosensitive drum with the toner contained in the developer. The toner inside the developing device decreases as a result of development. For this reason, the image forming device is equipped with a toner container that contains toner, and is configured to supply toner from the toner container to the developing device. The image forming device is equipped with a toner transport device that transports toner from the toner container to the developing device. The housing of the toner transport device has a toner receiving section that receives toner supplied from the toner container and guides it to the internal toner transport path. When toner passes through the toner receiving section, toner may adhere to and accumulate on the inner surface of the guide path of the toner receiving section, obstructing the flow of toner through the guide path. In order to remove these deposits, a conventional toner transport device is equipped with a removal member that comes into contact with the inner surface of the guide path to break down and remove the deposits.

However, because the removal member physically contacts the inner surface of the guide path, the removal effect decreases when the removal member deteriorates due to fatigue. In addition, toner may accumulate on the removal member itself, which may actually worsen the flow of toner into the guide path.

Patent document 1 discloses a proposal to suppress toner accumulation in the casing of a developing device using a vibration motor. By attaching the vibration motor to the toner receiving section of the toner transport device, it is possible to suppress toner accumulation in the internal guide path.

JP 2014-6411 A

In a configuration in which a toner transport device is provided with multiple toner receiving sections, multiple vibration motors may be provided corresponding to each of the multiple toner receiving sections in order to suppress or remove toner accumulation in each toner receiving section. However, when the vibration periods and phases of the multiple vibration motors match, resonance occurs. On the other hand, when the vibration periods of the vibration motors match but the phases are in opposite phase to each other, the vibration is damped.

The object of the present invention is to provide a toner transport device and an image forming device that can apply stable vibrations from multiple vibration motors to the destination of the vibrations in order to suppress or remove toner accumulation.

The toner transport device according to one aspect of the present invention is a toner transport device that transports toner. The toner transport device includes a housing having a toner transport path therein, a toner guide section provided in the housing and having an opening through which toner flows in and out and a guide passage that communicates from the opening to the toner transport path, and at least two vibration motors that impart vibrations to the toner guide section. Each of the vibration motors is started at a different timing from the others, and is driven and controlled by a drive signal that alternates between a first pulse and a second pulse with different pulse widths.

An image forming apparatus according to another aspect of the present invention includes the toner transport device, a developing device that develops an image using toner supplied from the toner transport device, and a control unit that starts each of the vibration motors at different timings and drives and controls each vibration motor with a drive signal that alternates between a first pulse and a second pulse having different pulse widths.

According to the present invention, it is possible to apply stable vibrations from multiple vibration motors to the destination of the vibrations in order to suppress or remove toner deposits.

FIG. 1 is a perspective view showing an image forming apparatus according to an embodiment of the present invention. FIG. 2 is a front view showing the image forming apparatus with the front cover of the housing open. FIG. 3 is a diagram showing an internal configuration of the image forming unit included in the image forming apparatus. FIG. 4 is a perspective view of the container mounting portion, the toner transport device, and the developing device, as viewed obliquely from above and behind. FIG. 5 is a perspective view showing a developing device provided in the image forming apparatus. FIG. 6 is a perspective view of the container mounting portion as viewed obliquely from below and rearward. FIG. 7 is a cross-sectional view showing the cross-sectional structure of the toner transport device and the developing device. FIG. 8 is a perspective view of the toner transport device as viewed from the rear side. FIG. 9 is a perspective view of the toner transport device as viewed from the front side. FIG. 10 is an exploded perspective view of a casing provided in the toner transport device. FIG. 11 is a perspective view showing a toner guide provided in the toner transport device. FIG. 12 is a perspective view showing the configuration of a side surface of a casing provided in the toner transport device. FIG. 13 is a side view showing the configuration of a side surface of a casing provided in the toner transport device. FIG. 14 is a perspective view showing a state in which the vibration unit is removed from a casing of the toner transport device. FIG. 15 is a perspective view showing a vibration unit included in the toner transport device. FIG. 16 is a perspective view showing a vibration unit provided in the toner transport device. FIG. 17 is an exploded view of a vibration unit provided in the toner transport device. FIG. 18 is a block diagram showing the connection relationship between the control unit and the vibration motor. 19A to 19C are diagrams showing waveforms of drive signals applied from the control unit to each vibration motor. FIG. 20 is a timing chart of the printing operation and a diagram showing waveforms of drive signals applied from the control unit to the supply motor and each vibration motor.

The following describes an embodiment of the present invention. Note that the embodiment described below is merely an example of the present invention and does not limit the technical scope of the present invention.

First Embodiment
A first embodiment of the present invention will be described below with reference to the drawings as appropriate. Fig. 1 is a diagram showing the configuration of an image forming apparatus 10 according to an embodiment of the present invention. For ease of explanation, the vertical direction in an installed state (as shown in Fig. 1) in which the image forming apparatus 10 can be used is defined as an up-down direction 6. In addition, a front side (front surface) on which an operation display unit 17 is provided in the installed state is defined as a front side, and a left-right direction 8 is defined with reference to the front surface of the image forming apparatus 10 in the installed state.

[Image forming apparatus 10]
The image forming apparatus 10 has at least a printing function. As shown in FIG. 1, the image forming apparatus 10 is a so-called tandem type color printer. The image forming apparatus 10 uses a developer containing toner. The image forming apparatus 10 may be any apparatus having a printing function, such as a multifunction machine having multiple functions including the printing function, or a fax machine. It is to be noted that the image forming apparatus 10 may be a printer, a copier, etc. Of course, the image forming apparatus 10 may not be one that forms a color image, but may be one that forms a single-color image.

The image forming device 10 includes an image reading unit 12 and an image forming unit 14. The image reading unit 12 performs a process of reading an image of a document, and is provided at the top of the image forming device 10. The image forming unit 14 performs a process of forming a color image based on an electrophotographic method, and is provided at the bottom of the image forming device 10. In addition, a sheet discharge unit 15 is provided to the right of the image forming unit 14.

A discharge space 21 is provided between the image forming unit 14 and the image reading unit 12. The sheet discharge unit 15 connects the image forming unit 14 and the image reading unit 12 vertically while forming the discharge space 21 between them.

The sheet discharge section 15 discharges the sheet material after image formation into the discharge space 21. A sheet discharge outlet 15A (see FIG. 3) is provided on the left side of the sheet discharge section 15 facing the discharge space 21. The sheet discharge outlet 15A is formed above an end 24 of the sheet tray 18, which will be described later. The sheet material is discharged from the sheet discharge outlet 15A.

The image forming unit 14 has a housing 11 as the device main body. Inside the housing 11, the various components that make up the image forming unit 14 are arranged. The housing 11 is composed of an exterior frame that covers the entire image forming unit 14, and an internal frame for supporting the various components that make up the image forming unit 14. The housing 11 has a generally rectangular parallelepiped shape.

The housing 11 has a front cover 11A and a side cover 11B. The front cover 11A and the side cover 11B cover an opening 11C (see FIG. 2) on the front of the housing 11. When the front cover 11A is opened, the inside of the image forming unit 14 is opened (see FIG. 2). The side cover 11B is provided on the upper side of the front cover 11A. The upper side of the opening 11C, which cannot be closed by the front cover 11A, is closed by the side cover 11B. FIG. 2 shows a state in which the side cover 11B has been removed and the front cover 11A is opened. A toner container 3 (toner container) is attached inside the housing 11 through the opening 11C.

Figure 3 is a diagram showing the internal configuration of the image forming unit 14. In Figure 3, the image reading unit 12 is omitted. The image forming unit 14 forms a color image on a sheet member such as a printing paper based on a so-called tandem method. As shown in Figure 3, the image forming unit 14 includes four image forming units 4, an intermediate transfer unit 5, an optical scanning device 13, a secondary transfer roller 20, a fixing device 16, a sheet tray 18, a sheet cassette 27, a feeding unit 28, an operation display unit 17 (see Figure 1), a transport path 26, a container mounting unit 30, a toner transport device 60 (an example of a toner transport device of the present invention), and a control unit 35 (an example of a control unit of the present invention).

The feeding unit 28 takes out the sheet members, which are the recording media stored in the sheet cassette 27, one by one and feeds the sheet members toward the transport path 26.

Each of the image forming units 4 (4Y, 4C, 4M, 4K) is provided below the intermediate transfer unit 5. The multiple image forming units 4 are arranged side by side along the left-right direction 8 that generally coincides with the running direction of the transfer belt 5A (the direction indicated by the arrow 19). From the left to the right side of the transfer belt 5A, the image forming unit 4Y for yellow, the image forming unit 4C for cyan, the image forming unit 4M for magenta, and the image forming unit 4K for black are arranged in a row in that order.

Each image forming unit 4 includes a photoconductor drum 41, a charging device 42, a developing device 44, a primary transfer roller 45, etc. The image forming unit 4 forms a toner image on the photoconductor drum 41 according to the electrophotographic method, and transfers the toner images to the transfer belt 5A of the intermediate transfer unit 5 in a sequentially superimposed manner. The transfer belt 5A can move in the direction of the arrow 19, and the toner images are sequentially transferred to the transfer belt 5A during the movement. The image forming unit 4Y forms a toner image on the surface of the photoconductor drum 41 with yellow toner. The image forming unit 4C forms a toner image on the surface of the photoconductor drum 41 with cyan toner, the image forming unit 4M with magenta toner, and the image forming unit 4K with black toner. The developing process of the toner image on the photoconductor drum 41 is performed by the developing device 44.

The developing device 44 develops images using a developer containing toner. FIG. 4 is a perspective view of the container mounting section 30, the toner transport device 60, and the developing device 44 as viewed from the rear side. FIG. 5 is a perspective view of the developing device 44. As shown in FIGS. 4 and 5, the developing device 44 is formed in a shape that is long in the front-rear direction 7. The container body 44A of the developing device 44 is provided with a toner supply section 44B (an example of the toner supply device of the present invention, see FIG. 5). The toner supply section 44B and a supply port 44C (see FIG. 5) are formed. As shown in FIG. 5, the toner supply section 44B is provided at one end of the container body 44A in the longitudinal direction, specifically, at the rear end when the developing device 44 is mounted inside the housing 11.

The developing device 44 is detachably mounted on the housing 11 to allow replacement. A support stand (not shown) for supporting the developing device 44 is provided on the internal frame of the housing 11. When the developing device 44 is attached to the support stand, toner can be supplied to the inside of the developing device 44 through the supply port 44C by the toner conveying device 60 described below.

As shown in FIG. 3, the intermediate transfer unit 5 is provided above the image forming unit 4 and below the container mounting section 30. The intermediate transfer unit 5 has a transfer belt 5A, a drive roller 5B, and a driven roller 5C. The transfer belt 5A is a belt member to which the toner images of each color formed on the photosensitive drum 41 of each image forming unit 4 are transferred. The transfer belt 5A is provided on the upper side of the photosensitive drum 41. The transfer belt 5A is an endless circular belt. The transfer belt 5A is rotatably supported by the drive roller 5B and the driven roller 5C that are provided at a distance in the left-right direction 8. The transfer belt 5A is supported so as to be stretched over the drive roller 5B and the driven roller 5C. When the surface of the transfer belt 5A passes between the photosensitive drum 41 and the primary transfer roller 45, the toner images are transferred from each photosensitive drum 41 in order in a superimposed manner.

The optical scanning device 13 irradiates the photoconductor drum 41 of each image forming unit 4 with laser light based on the input image data for each color. This forms an electrostatic latent image on each photoconductor drum 41.

The secondary transfer roller 20 is disposed opposite the drive roller 5B, sandwiching the vertically extending transport path 26 therebetween. The toner image on the transfer belt 5A is transferred to the sheet member by the transfer potential applied to the secondary transfer roller 20. The sheet member to which the toner image has been transferred is transported to the fixing device 16.

The fixing device 16 heats the toner image transferred to the sheet member to fix it to the sheet member, and has a heating roller 16A and a pressure roller 16B. The sheet member transported to the fixing device 16 is conveyed while being sandwiched between the heating roller 16A and the pressure roller 16B. During this conveyance, heat is transferred from the heating roller 16A to the toner image transferred to the sheet member, heating the toner image. This fixes the toner image to the sheet member. The sheet member is then discharged to the sheet tray 18 by the sheet discharge section 15.

As shown in FIG. 3, the sheet tray 18 is provided in the discharge space 21. The sheet tray 18 holds sheet materials that have passed through the fixing device 16 and been discharged to the outside from the sheet discharge port 15A of the sheet discharge section 15. The sheet tray 18 also serves as an exterior frame that forms the upper surface of the image forming section 14. The sheet materials discharged to the sheet tray 18 are loaded by stacking them upward. The upper surface (sheet placement surface) of the sheet tray 18 is formed with multiple ribs 18A (see FIG. 2) that extend in the left-right direction 8. The sheet materials discharged to the sheet tray 18 are supported by the upper ends of these ribs 18A.

The container mounting section 30 holds four toner containers 3 in which toner is stored. As shown in FIG. 3, the container mounting section 30 is provided above the intermediate transfer unit 5. A storage space 22 is formed between the intermediate transfer unit 5 and the sheet tray 18, and the container mounting section 30 is provided in the storage space 22. In other words, the sheet tray 18 is provided above the container mounting section 30, and the intermediate transfer unit 5 is provided below the container mounting section 30. Details of the container mounting section 30 will be described later.

The toner transport device 60 transports toner supplied from the toner container 3 mounted in the container mounting section 30 to the developing device 44. As shown in FIG. 4, the toner transport device 60 is provided rearward of the container mounting section 30 and each developing device 44. The toner transport device 60 will be described in detail later.

[Container mounting section 30]
Fig. 6 is a perspective view of the container mounting part 30 as viewed from diagonally below and behind. In both Fig. 4 and Fig. 6, a state in which the toner container 3 is mounted in the container mounting part 30 is shown. The container mounting part 30 is fixed to an internal frame of the housing 11. The container mounting part 30 removably mounts a plurality of toner containers 3 (toner containers). In other words, the toner containers 3 are removably mounted in the image forming apparatus 10 by the container mounting part 30.

The container mounting section 30 has a support frame 31 that supports each of the toner containers 3 of each color so that they can slide in the front-rear direction 7. In the support frame 31, the toner containers 3 of each color are arranged side by side along the left-right direction 8.

[Toner Container 3]
6, the toner container 3 is formed in a shape long in the front-rear direction 7. Each of the four toner containers 3 contains a toner of a color corresponding to each color of the image forming unit 4. Specifically, the toner container 3K contains black toner, the toner container 3M contains magenta toner, the toner container 3C contains cyan toner, and the toner container 3Y contains yellow toner. Since black toner is consumed the most, the toner container 3K is formed to have a larger width and volume than the other toner containers 3 (3Y, 3C, 3M).

A toner discharge port 32 is formed on the rear side of the bottom of the toner container 3, and a shutter member 33 is further provided to open and close the toner discharge port 32. The shutter member 33 is supported by a shutter support member 331 attached to the bottom of the toner container 3 so that it can slide between an open position and a closed position. When the toner container 3 is attached to the container attachment section 30, the shutter member 33 slides to open the toner discharge port 32.

At the rear end of the toner container 3, a transmission unit 50 is provided that receives the rotational driving force input from the image forming device 10 when the toner container 3 is attached to the container attachment unit 30. The transmission unit 50 includes a connecting member, a gear, and the like. The transmission unit 50 is connected to a joint (not shown) provided on the container attachment unit 30 in the attached state. The transmission unit 50 is also connected to a spiral-shaped transport member 34 (see FIG. 7) provided inside the toner container 3. As a result, when the rotational driving force is input to the transmission unit 50 in the attached state, the transmission unit 50 rotates the transport member 34. As a result, the toner inside the toner container 3 is transported to the toner discharge port 32 side.

The container mounting unit 30 of the image forming device 10 is provided with a resupply motor 51 (see FIG. 18) for replenishing toner. The resupply motor 51 supplies the rotational driving force to the transmission unit 50 to rotate the conveying member 34. The resupply motor 51 is driven and controlled by the control unit 35. A plurality of resupply motors 51 may be provided according to the number of toner containers 3, or a single motor may be provided that supplies a rotational driving force to the transmission unit 50 of each toner container 3.

The toner contained in the toner container 3 is supplied from the toner discharge port 32 to the toner transport device 60 (described later), which then transports the toner to the supply port 44C (see FIG. 5) of the developing device 44 that corresponds to the color of the supplied toner, and is supplied from the supply port 44C to the inside of the developing device 44.

The control unit 35 controls the operation of the image forming device 10 and the toner conveying device 60. The control unit 35 includes control devices such as a CPU, a ROM, and a RAM. The CPU is a processor that executes various types of arithmetic processing. The ROM is a non-volatile storage medium that stores a control program for causing the CPU to execute various types of arithmetic processing. The RAM is a volatile or non-volatile storage medium that stores various types of information. The control unit 35 may be realized, for example, by an IC such as an ASIC.

As shown in FIG. 18, the control unit 35 is connected to a plurality of vibration motors 72 (721, 722) provided in the toner transport device 60. The control unit 35 is also connected to a supply motor 51 provided in the container mounting unit 30. The control unit 35 supplies drive signals to the vibration motor 72 and the supply motor 51 to drive the vibration motor 72 and the supply motor 51.

[Toner conveying device 60]
Fig. 7 is a cross-sectional view seen from the rear side when the toner transport device 60, the container mounting unit 30, and the developing device 44 are cut along a cutting plane passing through the toner transport path 36 of the toner transport device 60. Figs. 8 and 9 are perspective views showing the configuration of the toner transport device 60, Fig. 8 being a perspective view of the toner transport device 60 seen from the rear side, and Fig. 9 being a perspective view of the toner transport device 60 seen from the front side. Fig. 10 is an exploded perspective view of a casing 61 provided in the toner transport device 60. Note that Fig. 8 shows a shutter support member 331 and a shutter member 33 provided in the toner container 3.

The toner transport device 60 is provided on the rear side of the container mounting section 30 and the developing device 44. The toner transport device 60 transports the toner supplied from the toner discharge port 32 of the toner container 3 to the supply port 44C of the developing device 44, and supplies the toner to the inside of the developing device 44 through the supply port 44C.

As shown in Figures 8 and 9, the toner transport device 60 includes a casing 61 (an example of the housing of the present invention), four toner guides 62, a transport member 65, and two vibration units 70.

The casing 61 is made of synthetic resin, for example ABS resin. The casing 61 is formed in a shape long in the horizontal direction (left-right direction 8). The casing 61 is composed of a first casing 611 (an example of a first divided casing) that constitutes the front housing, and a second casing 612 (an example of a second divided casing) that constitutes the rear housing. The first casing 611 and the second casing 612 are both formed in a shape long in the left-right direction 8, and divide the casing 61 in a short direction (front-back direction 7) perpendicular to the longitudinal direction. The casing 61 is formed by connecting the first casing 611 and the second casing 612 in the short direction.

Five connecting parts 63 (examples of connecting members) are provided on the upper part of the casing 61. As shown in FIG. 10, the connecting parts 63 are connecting members that connect the first casing 611 and the second casing 612, and have a so-called snap-fit structure. In this embodiment, of the five connecting parts 63, four connecting parts 63 (63A, 63B) provided on the left side of the casing 61 are disposed near the receiving port 38 and the guide passage 38A described below.

The connecting portion 63 is composed of a protruding piece 631 provided on the upper part of the first casing 611 and a locking claw 632 provided on the upper part of the second casing 612. The protruding piece 631 has an insertion hole into which the locking claw 632 is inserted in the connected state. When the first casing 611 and the second casing 612 are aligned in the short direction and joined to each other, each locking claw 632 is inserted into the insertion hole of the corresponding protruding piece 631. This firmly connects the protruding piece 631 and the locking claw 632, that is, the first casing 611 and the second casing 612 are connected. Note that a connecting portion (not shown) having the same configuration as the connecting portion 63 is also provided on the lower part of the casing 61.

As shown in FIG. 7, a toner transport path 36 for transporting toner is provided inside the casing 61. The toner transport path 36 is a passage for transporting toner supplied from the toner container 3 to the developing device 44. In this embodiment, the toner transport path 36 extends in the left-right direction 8 in the casing 61. The toner transport path 36 is divided into four paths corresponding to the four toner containers 3. Adjacent portions of each path are sealed by a seal member 37 to prevent the toner of each color from being mixed in the toner transport path 36.

As shown in FIG. 7, a spiral-shaped transport member 65 for transporting toner in the toner transport path 36 is provided inside the casing 61. The transport member 65 is provided in the toner transport path 36. The transport member 65 is a spiral shaft member with a spiral blade provided on a rotating shaft extending along the longitudinal direction (left-right direction 8) of the toner transport path 36. The transport member 65 rotates by receiving a driving force, thereby transporting toner in one direction in the toner transport path 36. In this embodiment, the transport member 65 transports toner supplied from the toner container 3 through the receiving port 38 described later toward the communication port 39 of the toner guide 62 described later. The toner transported to the communication port 39 falls downward while being guided by the toner guide 62, reaches the supply port 44C from the lower supply port 66 (toner supply port) at the lower end, and enters the inside of the developing device 44 through the supply port 44C.

8 and 9, a plurality of receiving ports 38 (one example of the opening of the present invention) are provided on the upper part of the casing 61. The receiving ports 38 are openings through which the toner from the toner container 3 flows in. In this embodiment, four receiving ports 38 are provided on the upper part of the casing 61 corresponding to the four toner containers 3. Each receiving port 38 is formed on the upper surface of the first casing 611. Each receiving port 38 is arranged at a predetermined distance in the left-right direction 8 on the upper part of the casing 61. Each receiving port 38 penetrates the upper wall surface of the casing 61 downward and communicates with the toner transport path 36. The toner supplied from the toner container 3 flows into the receiving port 38. In the portion from each receiving port 38 to the toner transport path 36, a guide passage 38A (see FIG. 7) is formed to guide the toner supplied from the toner container 3 from the receiving port 38 to the toner transport path 36. The configuration including the receiving port 38 and the guide passage 38A corresponds to the toner guide portion of the present invention.

Each receiving port 38 is provided at a position that allows communication with the toner discharge port 32 (see FIG. 7) formed on the toner container 3 when the corresponding toner container 3 is attached to the container attachment section 30 (hereinafter referred to as the container attached state). In other words, in the container attached state, the receiving port 38 is provided below the toner discharge port 32. Note that in order to prevent toner leakage from the toner discharge port 32, the toner discharge port 32 is in close contact with the receiving port 38 in the container attached state.

Furthermore, four communication openings 39 are formed in the lower wall surface 61A of the casing 61 (see FIG. 7). Each communication opening 39 is provided for each passage in the toner transport path 36 corresponding to each color of toner. As shown in FIG. 7, a toner guide 62 is provided corresponding to each communication opening 39.

Figure 11 is an enlarged perspective view of the toner guide 62. The toner guide 62 has a cylindrical guide portion 62A with a square cross section that extends downward from the communication port 39. The inside of the guide portion 62A is a passage through which the toner is guided downward. The upper end of the toner guide 62 is connected to the communication port 39. A lower supply port 66 is formed at the lower end of the toner guide 62. The toner that flows into the inside of the toner guide 62 from the communication port 39 moves downward under its own weight while being guided by the guide portion 62A.

A shutter member 67 is provided at the lower end of the toner guide 62. The shutter member 67 is a member for opening and closing the lower supply port 66, and is supported at the lower end of the toner guide so as to be slidable between a closed position where the lower supply port 66 can be closed and an open position (position shown in FIG. 11) where the lower supply port 66 can be opened. The shutter member 67 is biased in a closing direction from the open position toward the closed position by a spring member (not shown). When the developing device 44 is mounted to the mounting position in the housing 11, a part of the developing device 44 presses the abutment portion 68 of the shutter member 67 backward. Receiving the pressing force at this time, the shutter member 67 moves in an opening direction from the closed position toward the open position against the biasing force of the spring member. This opens the lower supply port 66, and toner moving downward through the toner guide 62 can flow into the inside of the developing device 44.

Each of the multiple receiving openings 38 receives toner supplied from the toner container 3 and guides it to the internal toner transport path 36. For this reason, toner may adhere to and accumulate on the inner surface of the guide path 38A leading from the receiving opening 38 to the toner transport path 36, hindering the movement of toner in the guide path 38A. In this embodiment, a vibration unit 70 (described later) is attached to the casing 61 to transmit appropriate vibrations to all of the multiple receiving openings 38 and multiple guide paths 38A using a number of vibration motors 72 that is fewer than the number of receiving openings 38 installed, and to effectively remove toner deposits that accumulate on the inner surface of each of the multiple guide paths 38A.

[Vibration unit 70]
12 to 14 are diagrams showing the configuration of the side surface of the casing 61. Fig. 14 shows a state in which the vibration unit 70 is removed from the casing 61. As shown in Fig. 12 and other figures, the vibration unit 70 is provided on the rear side surface 61B of the casing 61, that is, the rear side surface 61B of the second casing 612. In this embodiment, both of the two vibration units 70 have the same configuration and are provided on the side surface 61B of the casing 61 at a predetermined interval in the longitudinal direction of the casing 61.

The two vibration units 70 are configured to apply appropriate vibrations to all four receiving openings 38 and four guide passages 38A so that toner does not accumulate in each of the four receiving openings 38 and four guide passages 38A. Each vibration unit 70 has a bracket 71 and a vibration motor 72 (vibration generating unit).

The bracket 71 is fixed to the side surface 61B via a boss 73 (an example of a leg of the present invention) provided on the side surface 61B, which will be described later. The bracket 71 is made of a material with a higher natural frequency than the casing 61, and in this embodiment, is formed into a plate shape using a sheet metal member such as carbon steel or alloy steel. The bracket 71 is formed in an elongated shape along the longitudinal direction of the casing 61. In addition, both ends (upper end and lower end) of the bracket 71 in the short direction are each bent outward by 90 degrees to obtain higher strength and rigidity.

Figures 15 and 16 are perspective views showing the vibration unit 70 alone. Figure 17 is an exploded perspective view of the vibration unit 70. As shown in Figure 15 and other figures, a plurality of openings 81 to 88 are formed in the side surface 71A on one side (rear side) of the bracket 71, penetrating the bracket 71. The openings 81 and 82 are formed at both ends in the longitudinal direction of the bracket 71. An opening 83 having a smaller diameter than the opening 81 is formed near one opening 81, and an opening 84 having a smaller diameter than the opening 82 is formed near the other opening 82. The openings 83 and 84 are used when temporarily fixing the bracket 71 to the side surface 61B of the casing 61. The openings 81 and 82 are used to fix the bracket 71, which is temporarily fixed to the side surface 61B, with a screw 92 (see Figure 13) or the like.

As shown in FIG. 16, a vibration motor 72 is attached to the side surface 71B (an example of an opposing surface) on the other side (front side) of the bracket 71. This places the vibration motor 72 in the space between the side surface 71B and the side surface 61B. The vibration motor 72 of each of the two vibration units is, for example, a DC motor with an eccentric weight fixed to the output shaft, and each vibration motor 72 is driven by supplying a DC current under the control of the control unit 35 (see FIG. 3). The vibration motor 72 is driven to rotate and the eccentric weight rotates, generating vibration. This vibration is transmitted to the side surface 61B of the casing 61 via the bracket 71 and the boss 73. Note that the vibration motor 72 is merely one example of a vibration generating unit, and any configuration that generates vibration can be applied.

As shown in FIG. 17, three positioning pins 95-97 are provided on the mounting surface 72A of the vibration motor 72. The positioning pins 95-97 of the vibration motor 72 are inserted into the openings 85-87 formed in the bracket 71, thereby temporarily fixing the vibration motor 72 to the side surface 71B of the bracket 71. In this temporarily fixed state, a screw 91 (see FIG. 15) is screwed into a screw hole 98 formed in the vibration motor 72 through the opening 88. This firmly fixes the vibration motor 72 to the side surface 71B of the bracket 71.

As shown in FIG. 14, four cylindrical bosses 73 are provided on the side surface 61B of the casing 61. In other words, each boss 73 is provided on the side surface 61B on the rear side of the second casing 612. The bracket 71 is supported by each boss 73. Each boss 73 protrudes outward (rearward) from the side surface 61B of the casing 61. Each boss 73 is provided on the side surface 61B at a predetermined interval along the longitudinal direction of the casing 61. Of the four bosses 73, one vibration unit 70 is attached to a pair of bosses 73A on the right side, and the other vibration unit 70 is attached to a pair of bosses 73B on the left side. The spacing between the pair of bosses 73A is the same as the spacing between the pair of bosses 73B.

Each boss 73 is formed with a reinforcing rib 74. One or more reinforcing ribs 74 are formed on the outer peripheral surface of each boss 73. The reinforcing ribs 74 extend in the protruding direction of the boss 73.

A positioning pin 75 for temporary fixing is provided near each boss 73. The positioning pin 75 is formed integrally with the casing 61. The vibration unit 70 is temporarily fixed to the side surface 71A of the bracket 71 by inserting each positioning pin 75 through the openings 82, 83 of the bracket 71. In this temporary fixing state, a screw 92 (see FIG. 13) is screwed from the openings 81, 82 into a screw hole formed in the corresponding boss 73. This firmly fixes the vibration unit 70 to the side surface 61B of the casing 61.

Each boss 73 is formed integrally with the casing 61. That is, the boss 73 is made of the same material as the casing 61. Each boss 73 is provided at a position corresponding to the receiving port 38 at the upper end of the side surface 61B of the casing 61. Furthermore, the protruding length of each of the four bosses 73 is the same. In this embodiment, the bosses 73 are fixed to positions near each of the multiple receiving ports 38 in the casing 61. Specifically, a pair of bosses 73A are provided directly below the corresponding receiving port 38, and a pair of bosses 73B are provided near the corresponding receiving port 38. Furthermore, in this embodiment, each boss 73 is provided near the connecting portion 63.

In the toner conveying device 60 of this embodiment, the vibration unit 70 configured as described above is fixed to the side surface 61B of the casing 61. When the vibration motor 72 of the vibration unit 70 is driven by the control unit 35, the vibration generated by the vibration motor 72 is transmitted to the side surface 61B of the casing 61 via the bracket 71 and the boss 73. As described above, the boss 73 is fixed to a position near each of the two receiving openings 38 in the casing 61, so the vibration transmitted from the boss 73 to the casing 61 is transmitted to the corresponding two receiving openings 38 and the guide passage 38A without being significantly attenuated. As a result, it is possible to effectively remove the toner deposits accumulated in the corresponding two receiving openings 38 and the guide passage 38A, and toner adhesion to the inner surface of the receiving opening 38 and the guide passage 38A can be suppressed. Furthermore, with the vibration unit 70 described above, the vibration of one vibration motor 72 can be transmitted to two corresponding receiving openings 38 and guide passages 38A, so the number of vibration motors 72 to be installed can be reduced compared to a configuration in which a vibration motor 72 is provided for each of multiple receiving openings 38 and guide passages 38A.

In addition, in this embodiment, the vibration motor 72 is attached to the side surface 71B of the bracket 71, and is disposed in the space between the side surface 71B of the bracket 71 and the side surface 61B of the casing 61. As a result, the vibration motor 72 is not exposed to the outside of the casing 61, so the space outside the side surface 61B of the casing 61 can be reduced. In addition, the bracket 71 can protect the vibration motor 72 from external impacts, etc.

In the above embodiment, the casing 61 is configured to connect the first casing 611 and the second casing 612 in the front-rear direction 7, the receiving port 38 and the guide passage 38A are provided in the first casing 611, and the boss 73 is provided on the side surface 61B of the second casing 612. In this configuration, the boss 73 is provided at the upper end of the side surface 61B at a position corresponding to the receiving port 38 and the guide passage 38A, and the connecting portion 63 is provided near the receiving port 38 and the guide passage 38A. Therefore, the vibration of the vibration unit 70 is transmitted to the receiving port 38 and the guide passage 38A from two paths. That is, the vibration is transmitted from the boss 73 through the second casing 612, the joint with the second casing 612 (not shown), and the first casing 611 to the receiving port 38 and the guide passage 38A, and the vibration is also transmitted from the boss 73 through the second casing 612, the connecting portion 63, and the first casing 611 to the receiving port 38 and the guide passage 38A. In this way, since the vibration is transmitted to the receiving port 38 and the guide passage 38A from two routes, in the casing 61 composed of two members as described above, it is possible to effectively transmit the vibration of the vibration unit 70 to the receiving port 38 and the guide passage 38A.

In the above embodiment, a configuration in which two vibration units 70 are mounted for four receiving openings 38 and guide passages 38A is exemplified, but the present invention is not limited to this configuration. For example, the vibration unit 70 may be configured to have one long bracket supported by four bosses 73 and one or two vibration motors fixed to the bracket.

In addition, in the above embodiment, a configuration in which the vibration unit 70 is attached to the side surface 61B of the casing 61 is exemplified, but, for example, the vibration unit 70 may be attached to the side surface of the casing 61 opposite to the side surface 61B.

In addition, in the above embodiment, a configuration in which the casing 61 can be separated into two casings, the first casing 611 and the second casing 612, is exemplified, but the present invention is not limited to this configuration. For example, the present invention can be applied even if the casing 61 is not separated but is constructed as one piece.

In a configuration in which vibrations are applied from multiple vibration motors 72 to multiple receiving openings 38 and multiple guide passages 38A, when the multiple vibration motors 72 are driven, if the vibration periods and phases of the vibration motors 72 match, the vibrations resonate with each other. On the other hand, if the vibration periods of the vibration motors 72 match but are in opposite phases, they cancel each other out and the vibrations are damped. In this embodiment, the control unit 35 drives and controls each vibration motor 72 so that stable vibrations can be applied to the destination of the vibrations.

Specifically, as shown in FIG. 19A, the control unit 35 controls the vibration motors 721 and 722 to start at different timings and drive them intermittently at a predetermined interval after starting. For example, the control unit 35 outputs a drive signal Sig11 to one vibration motor 721 at time T10 to start the vibration motor 721, and outputs a drive signal Sig12 to the other vibration motor 722 at time T20, which is delayed by Δt1 from time T10, to start the vibration motor 722. Specifically, the control unit 35 has switching elements (not shown) corresponding to the drive signals Sig11 and Sig12, and controls the on/off timing of the switching elements to make the output timing of the drive signals Sig11 and Sig12 different. It is also possible to differentiate the output timing of the drive signals Sig11 and Sig12, for example, by providing a delay circuit (not shown) with a predetermined time constant in the signal line between the control unit 35 and the other vibration motor 722. In this case, the difference in the start timing of the vibration motors 721 and 722 can be adjusted by setting the time constant of the delay circuit to an appropriate value.

In the example of FIG. 19A, the drive signals Sig11, Sig12 output to each vibration motor 721, 722 are square wave signals (pulse signals) with a duty ratio of 50%, and the Δt1 is set to be the same as the interval from the rising edge to the falling edge of each square wave (the duration that the pulse is on). By controlling the drive in this manner, when the vibration motor 721 is vibrating (driving), the vibration motor 722 stops, and when the vibration motor 721 is stopped, the vibration motor 722 vibrates (driving). The above-mentioned operation is repeated until the drive signal from the control unit 35 stops, causing each vibration motor 721, 722 to vibrate.

As shown in FIG. 19B, the control unit 35 outputs a drive signal Sig11 to one vibration motor 721 at time T10 to start it, and outputs a drive signal Sig12 to the other vibration motor 722 at time T30, which is delayed by Δt2 from time T10, to start it. In the example of FIG. 19B, the drive signals output to each vibration motor 721, 722 are square wave signals (pulse signals) with a duty ratio of 50%, but the Δt2 is half the interval from the rising edge to the falling edge of each square wave (the duration during which the pulse is on). By controlling the drive in this way, when the vibration motor 721 starts to vibrate (drive), the vibration motor 722 is stopped, and when Δt2 has elapsed since the vibration motor 721 vibrates, the vibration motor 722 starts to vibrate (drive). After that, when Δt2 has elapsed, the vibration of the vibration motor 721 stops, and when Δt2 has elapsed, the vibration motor 722 also stops. The above-described operations are repeated until the drive signal from the control unit 35 stops, causing each of the vibration motors 721 and 722 to vibrate.

As shown in FIG. 19C, the control unit 35 outputs a drive signal Sig11 to one vibration motor 721 at time T10 to start it, and outputs a drive signal Sig12 to the other vibration motor 722 at time T40, which is delayed by Δt3 from time T10, to start it. In the example of FIG. 19C, the drive signals Sig11 and Sig12 output to each vibration motor 721 and 722 are square wave signals (pulse signals) with a duty ratio of less than 50%, and the Δt3 is longer than the interval from the rising edge to the falling edge of each square wave (the duration during which the pulse is on). By controlling the drive in this way, the vibration motor 722 is stopped from when the vibration motor 721 starts vibrating (driving) until the vibration stops, and the vibration motor 722 starts vibrating (driving) after the vibration motor 721 has completely stopped. Thereafter, vibration motor 721 remains stopped until vibration of vibration motor 722 stops, and then vibration motor 721 starts vibrating after vibration of vibration motor 722 has completely stopped. The above-described operation is repeated until the drive signal from control unit 35 stops, causing each of vibration motors 721 and 722 to vibrate.

Second Embodiment
A second embodiment of the present invention will be described below with reference to Fig. 20. In this embodiment, the drive control of vibration motors 721 and 722 by the control unit 35 is different from that of the first embodiment described above, but other configurations are the same as those of the first embodiment. Therefore, in the following, only the configurations that differ from the first embodiment will be described, and descriptions of the other configurations will be omitted.

In this embodiment, as in the first embodiment described above, the control unit 35 controls the drive of each of the vibration motors 721, 722 so that the vibration motors 721, 722 are started at different timings and driven intermittently at a predetermined interval after starting, as shown in FIG. 20. In other words, the control unit 35 outputs a drive signal Sig11 to start one vibration motor 721 at time T50, and then outputs a drive signal Sig12 to the other vibration motor 722 at time T60, which is delayed by Δt4 from time T50, to start the other vibration motor.

In this embodiment, as shown in FIG. 20, the control unit 35 outputs the drive signals Sig11 and Sig12 to each vibration motor 721 and 722 as a rectangular wave signal (pulse signal) in which two rectangular waves (first and second pulses) with different pulse widths alternate in succession. Here, the pulse width is the interval from the rising edge to the falling edge of the rectangular wave (the duration during which the pulse is on). In other words, of the two rectangular waves, the pulse width d1 of the first pulse P1 that appears first after starting is different from the pulse width d2 of the second pulse P2 that appears next. Specifically, the pulse width d1 of the first pulse P1 is shorter than the pulse width d2 of the second pulse P2. In addition, the first pulse P1 and the second pulse P2 alternate at a predetermined interval (for example, the same interval as the pulse width of the first pulse P1).

In this embodiment, Δt4 is a time difference that is less than the interval d3 between the rising edge of the first pulse P1 and the falling edge of the second pulse P2. With this time difference, the vibration motor 721 is started first, and then the vibration motor 722 is started. Δt4 is set within a range that is greater than 0 and smaller than the interval d3. In the example of FIG. 20, Δt4 is set to a time difference that is half the pulse width d1 of the first pulse P1.

By controlling the driving of the vibration motors 721 and 722 in this way, when the vibration motor 721 starts vibrating (driving) first at time T50 by the first pulse P1 of the driving signal Sig11, the vibration motor 722 is still stopped. Then, at time T60, when Δt4 has elapsed since the vibration motor 721 started vibrating, the vibration motor 722 starts (driving) by the first pulse P1 of the driving signal Sig12. After that, when Δt4 has elapsed, the first pulse P1 of the driving signal Sig11 falls and the vibration of the vibration motor 721 stops, and when Δt4 has elapsed, the first pulse P1 of the driving signal Sig12 falls and the vibration motor 722 also stops. Then, after the first pulse P1 of each of the driving signals Sig11 and Sig12 falls, when the predetermined interval has elapsed, each of the vibration motors 721 and 722 is driven by the second pulse P2 with a pulse width d2. The vibration motor 721 operates with the first pulse P1 and the second pulse P2 until the drive signal Sig11 from the control unit 35 stops at time 61, and the vibration motor 721 operates with the first pulse P1 and the second pulse P2 until the drive signal Sig12 stops at time 62.

In this embodiment, during the development operation time t70 during which the development operation is performed by the image forming unit 4 of the image forming apparatus 10, the drive signals Sig11 and Sig12 are output to the vibration motors 721 and 722. In the example of FIG. 20, the drive signal Sig11 is output to the vibration motor 721 at the timing (time T50) when the development operation is started, and the output of the drive signals Sig11 and Sig12 is stopped at the timing (time T51) when the development operation is completed. Here, the development operation time t70 is the time from when the developing device 44 starts developing a toner image on the photoconductor drum 41 in the image formation process on one sheet member to when the development is completed. In other words, the development operation time t70 is the period during which the operation of consuming toner is performed in the image formation process on one sheet member. Toner is consumed during the development operation. Therefore, in order to prevent the density of the printed surface of the sheet member from decreasing due to toner consumption, the control unit 35 outputs a square wave signal shown in FIG. 20 to the supply motor 51 during printing operation to intermittently drive the supply motor 51, thereby supplying toner from the toner container 3 to the toner conveying device 60. In other words, as shown in FIG. 20, the control unit 35 drives the vibration motors 721 and 722 during the toner supply operation, and stops the vibration motors 721 and 722 when the toner supply operation is not being performed.

As described above, the toner conveying device 60 according to each of the above-mentioned embodiments has two vibration units 70 configured as described above fixed to the side surface 61B of the casing 61, and the vibration motors 72 (721, 722) of each vibration unit 70 are started at different start timings by the control unit 35 and driven intermittently as described above. This makes it difficult for the vibration period and phase of each vibration motor 72 to match, and vibration resonance does not continue while each vibration motor 72 is being driven.

In addition, the vibration phases of the vibration motors 72 are less likely to be in opposite phase to each other, and the vibration does not significantly attenuate while each vibration motor 72 is being driven. This makes it possible to stably transmit appropriate vibrations to all of the multiple receiving openings 38 and multiple guide passages 38A to which the vibrations are transmitted. As a result, toner deposits that have accumulated on the inner surface of each of the multiple guide passages 38A can be effectively removed, or toner accumulation can be suppressed.

In the above-described embodiments, a configuration in which a vibration motor 72 is provided in each of the two vibration units is illustrated, but the present invention is not limited to this configuration. For example, the present invention can also be applied to a configuration in which a vibration motor 72 is attached to each of the casing 61 in the vicinity of each guide passage 38A.

In addition, in each of the above-described embodiments, a configuration is illustrated in which vibration is applied to the toner guide portion (including the receiving port 38 and the guide passage 38A) that receives toner from the toner container 3 and guides it to the toner transport path 36, but the present invention may be configured to effectively apply vibration to either the receiving port 38 or the guide passage 38A. In addition, the present invention can also be applied to a configuration in which vibration is applied to the toner guide 62 that guides toner from the toner transport path 36 through the communication port 39 formed in the casing 61 to the supply port 44C of the developing device 44. In this case, the toner guide 62 corresponds to the toner guide portion of the present invention. Also, the vibration motor 72 is provided near each toner guide 62.

3: toner container 4: image forming unit 5: intermediate transfer unit 10: image forming device 11: housing 14: image forming section 30: container mounting section 31: support frame 32: toner discharge port 33: shutter member 34: transport member 35: control section 36: toner transport path 37: seal member 38: receiving port 38A: guide passage 39: communication port 44: developing device 44A: container body 44B: toner supply section 44C: supply port 50: transmission section 60: toner transport device 61: casing 61A: lower wall surface 61B: side surface 62: toner guide 62A: guide section 65: transport member 66: lower supply port 67: shutter member 68: contact section 70: vibration unit 71: bracket 71A: side surface 71B: side surface 72: vibration motor 72A: mounting surface 73 : Boss 74 : Reinforcement rib 75 : Positioning pin

Claims (5)

A toner conveying device that conveys toner,
a housing having a toner transport path therein;
a toner guide section provided in the housing, the toner guide section having an opening through which the toner flows and a guide passage communicating from the opening to the toner transport path;
At least two vibration motors that impart vibration to the toner guiding portion,
The vibration motors are started at different timings and are driven and controlled by a drive signal that alternately includes a first pulse and a second pulse having different pulse widths. The toner conveying device according to claim 1, wherein each of the vibration motors is started with a time difference less than the interval between the rising edge of the first pulse and the falling edge of the second pulse. The toner conveying device according to claim 1 or 2, wherein the vibration motor has an eccentric weight attached to the output shaft. A toner transport device according to any one of claims 1 to 3,
a developing device that develops the image using the toner supplied from the toner conveying device;
a control unit that starts each of the vibration motors at different timings and drives and controls each vibration motor with a drive signal that alternates between a first pulse and a second pulse having different pulse widths. a toner supply device that supplies toner to the opening of the toner conveying device,
5. The image forming apparatus according to claim 4 , wherein the control unit drives each vibration motor when a toner supply operation is being performed to supply toner to the opening during a development operation by the developing device, and stops each vibration motor while the development operation is not being performed and the toner supply operation is not being performed .

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